Overview

Product Details

Fast Zero Crossing Detector

The LT1116 is an ultra fast (12ns) comparator designed for sensing signals near the negative supply. The input common mode range extends from 2.5V below the positive supply down to the negative supply rail. Like the LT1016, this comparator is specifically designed to interface directly to TTL logic with complementary outputs. The comparator may operate from either a single 5V supply or dual ±5V supplies. Tight offset voltage specifications and high gain allow the LT1116 to be used in precision applications.


The LT1116 is designed for improved speed and stability for a wide range of operating conditions. The output stage provides active drive in both directions for maximum speed into TTL logic or passive loads, yet it has minimal cross-conduction current. Unlike other fast comparators, the LT1116 remains stable even for slow transitions through the active region, which eliminates the need to specify a minimum input slew rate.


The LT1116 has an internal, TTL compatible latch for retaining data at the outputs. The latch holds data as long as the latch pin is held high. Device parameters such as gain, offset, and negative power supply current are not significantly affected by variations in negative supply voltage.


The zero crossing detector in Figure above demonstrates the use of a fast clamp diode. Recovery, from 500mV overdrive below V–, for this circuit is approximately 18ns.


Tools & Simulations

LTspice

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

LTspice